Misc hardening changes for 5.19-rc1
Hi Linus,
Please, pull the following hardening changes that I've been collecting
in my tree during the last development cycle. All of them have been
baking in linux-next.
Replace open-coded instances with size_t saturating arithmetic helpers:
- virt: acrn: Prefer array_size and struct_size over open coded arithmetic (Len Baker)
- afs: Prefer struct_size over open coded arithmetic (Len Baker)
Thanks
--
Gustavo
virt: acrn: Prefer array_size and struct_size over open coded arithmetic
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the array_size() helper to do the arithmetic instead of the
argument "count * size" in the vzalloc() function.
Also, take the opportunity to add a flexible array member of struct
vm_memory_region_op to the vm_memory_region_batch structure. And then,
change the code accordingly and use the struct_size() helper to do the
arithmetic instead of the argument "size + size * count" in the kzalloc
function.
This code was detected with the help of Coccinelle and audited and fixed
manually.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Acked-by: Fei Li <fei1.li@intel.com>
Signed-off-by: Len Baker <len.baker@gmx.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2 files changed
